Monday, December 21, 2015

A private company, Space X, has, finally, managed to safely land the first stage of its Falcon 9 spacecraft back on Earth in Florida while successfully deploying several satellites into Earth orbit. The Falcon 9 upper stage booster, however, will not be recovered which, of course, makes this spacecraft only partially reusable-- just as NASA's Space Shuttle was.

NASA, of course, operated its partially reusable crewed spacecraft (the Space Shuttle) for
more than 30 years, recovering the reusable space
plane (Space Shuttle Orbiter) and twin solid rocket boosters (SRBs) after every flight. But the dramatically lower cost that was predicted for the Space Shuttle program never came to fruition thanks to a couple of fatal accidents and a high launch demand that never became a reality-- for both commercial and political reasons.

It should also be noted that NASA's cancelled Ares I program was also supposed to have a recoverable and reusable first stage based on the legacy of the Space Shuttle's solid rocket boosters.

The next step for Space X will be to refurbish the recovered Falcon 9 booster and its engines in order see if the first stage booster can successfully fly again and be successfully recovered again. How costly and reliable-- and safe-- a refurbished Falcon 9 booster will be is the next question for Space X. But recovering the Falcon 9 first stage while also successfully launching its payloads into orbit is a major milestone for a private space launch company.

Space X duly deserves to be congratulated for accomplishing this first important phase in its goal towards a reusable space launch vehicle!

Saturday, November 28, 2015

Originally utilized for human operations withing cis-lunar space in the 2020s, the reusable LOX/LH2 fueled ETLV-2 now heads towards its first crewed rendezvous and landing on the surface of the martian moon, Phobos, in 2031.

by Marcel F. Williams

NASA suggest that the first human missions to Mars will occur sometime in the 2030s. While the Obama administration has merely suggested a Mars flyby for the first crewed interplanetary voyage, others have proposed much more ambitious early human missions near the vicinity of the Red Planet. One frequent proposal is for a crewed journey to the orbit of Mars. Such an orbital mission could also include landings on at least one or both of the martian moons: Phobos and Deimos.

However, any serious efforts to transport humans on multi-year interplanetary voyages has to resolve the inherent problems of enhanced exposure to cosmic radiation and major solar events. Also, the deleterious effects of long term exposure to a microgravity environment over the course of several months and even years has to be resolved.

Mass shielding habitat areas with at least 30 centimeters of water could protect astronauts from the dangers of major solar storms while also enabling multiyear round trip missions to Mars and Venus without excessive exposure to cosmic radiation-- even during solar minimum conditions. The deleterious effects of microgravity on the human body could also be eliminated or, at least, substantially reduced by transporting astronauts aboard rotating interplanetary vessels with twin counterbalancing habitat modules.

However, a water shielded spacecraft with rotating habitat modules would substantially increase the mass of a crewed interplanetary vessel. One way to compensate for the increase in vehicle mass would be to launch the interplanetary vessel from one of the Earth-Moon Lagrange points-- instead of from LEO. This could shave off at least 2.8 km/s of delta-v requirement for an interplanetary mission. Dumping the water shielding for the twin habitat modules just a few hours, or a few days, before final trajectory burns into orbit could also substantially reduce the propellant requirements for an interplanetary vehicle. Finally, utilizing pre-deployed propellant producing water depots supplied with water from the Moon's low gravity well could also substantially reduce the propellant requirement for a reusable interplanetary vehicle.

In 2030, under this scenario, eight American astronauts and four foreign astronauts will depart from Earth-Moon Lagrange point four (EML4) towards a flyby of the planet Venus and then, a few months later, into high Mars orbit. During the interplanetary mission, astronauts will visit both of the martian moons, Phobos and Deimos, returning to Earth after the 22 month mission with a significant tonnage and variety of regolith samples from the moons of Mars. Water exported from the surface of the Moon from one of the lunar poles will be used to provide the water and propellant needed for the interplanetary mission.

Propellant producing water depot (WPD-LV-5A) on the lunar surface next to a mobile water tanker, LOX/LH2 cryotanker, and a Water Bug mobile microwave water extraction robot.

Nomenclature:

ETLV-2 (Extraterrestrial Landing Vehicle): Reusable LOX/LH2 vehicle capable of landing crews on the surface of the Moon or on the moons of Mars.

CLV-5B: Cargo
landing vehicles originally utilized to land large payloads on the lunar
surface but that are later utilized as reusable water tankers by
latching a water bag to the top of the spacecraft.

CLV-5A:
Reusable cargo landing vehicle specifically designed to transport water, regolith, or other heavy cargo from the lunar surface to the Earth-Moon Lagrange points.

February 2031: OTV-400 trajectory burn places Odyssey into a high Mars orbit.

February, March, and April of 2031: Two crewed ETLV-2 missions to the martian moon, Deimos and two crewed missions to the surface of Phobos

April 2031: OTV-400 trajectory burns transports Odyssey spacecraft from high Mars orbit into an Earth transfer orbit.December 2031: OTV-400 trajectory burns places the Odyssey spacecraft back into a halo orbit at EML4.

Maximum radiation exposure during the 18 month mission during solar minimum conditions (under 30 cm of water shielding aboard the Odyssey and including 10 days of temporary full exposure during orbital insertion and ETLV-2 visits to Phobos and Deimos): less than 50 Rem.

CLV-5A water tanker capable of transporting more than 50 tonnes of lunar water to the Earth-Moon Lagrange points. Mobile water tanker and a mobile LOX/LH2 cryotanker are near the shuttle spacecraft.

Cis-Lunar Space

During the early 2020s, a series of SLS cargo launches will be utilized to deploy a water and propellant producing and exporting infrastructure at one of the lunar poles . So starting in 2026, this will allow NASA to to focus its priorities on deploying the interplanetary infrastructure that will be necessary to take humans to the orbit of Mars in 2031-- and eventually to the surface of Mars in 2036. Under this scenario, the interplanetary infrastructure needed to accomplish these goals will mostly be derived from the technology and infrastructure developed for the cis-lunar program.

CLV-5A rendezvous with WPD-OTV-400 at EML4 to transfer more than 50 tonnes of lunar water. The orbiting depot will be capable of storing up to 1000 tonnes of water and up to 400 tonnes of LOX/LH2 propellant.

2030

Access to Orbit

In
February of 2030, three American Commercial Crew vehicles will
launch eight American astronauts plus four foreign astronauts from terrestrial launch facilities to low Earth orbit (LEO). All three of the Commercial
Crew vehicles will dock at LEO Way Station (LWS) that was originally deployed to LEO back in 2020. Simply derived from SLS hydrogen propellant tank technology and deployed by a single SLS launch, the LWS will be substantially cheaper than the hyper expensive ISS laboratory.

Rather than outsourcing technological participation from foreign space agencies, NASA will charge foreign space agencies $150 million for each foreign astronaut trained to participate in
NASA's first interplanetary mission. So the inclusion of four foreign astronauts in the interplanetary mission will shave off $300 million in cost to NASA-- and the tax payers. Foreign space agencies whose astronauts are participating in the Mars orbital mission
will receive up to 10 kilograms of material retrieved by astronauts and robots from the surfaces
of the martian moons, Deimos and Phobos.

An OTV-400 interplanetary booster rendezvous with a WPD-OTV-400 at EML4 to receive up to 400 tonnes of LOX/LH2 propellant. The WPD-OTV-400 produces propellant from lunar water when it is docked to a 1.2 MWe solar array (seen in the background) which is also located at EML4.

EML4

Docked at the LEO Way Station will be
two reusable ETLV-2 vehicles. Originally deployed by the SLS during the lunar outpost program of the early
2020s, each ETLV-2 vehicle will perform orbital transfer duties, transporting the international crew of 12 from LEO to EML4 ( Earth-Moon
Lagrange Point Four) in approximately two days at a slightly higher and more propellant expensive delta-v.

The LOX/LH2 propellant needed to fuel the
ETLV-2 vehicles will come from a LEO
orbiting propellant producing water depot (WPD-OTV-400). The LEO orbiting WPD-OTV-400 was
originally deployed by the SLS in the 2020's for cis-lunar operations.

WPD-OTV-400 depots will be capable of storing up to 400 tonnes of
LOX/LH2 propellant and up to 1000 tonnes of water. Some
of the water for the orbital depot will arrive as additional payload from Earth aboard SLS and other launch vehicles with some extra payload availability beyond the regular payloads that they will be deploying. But most of the water for the
LEO water/propellant depot will originate from the
surface of the Moon.

When running low on water and propellant, the LEO orbiting WPD-OTV-400
uses the remaining 50 tones of stored propellant to transport itself to EML4. There it
is supplied
with water and propellant from another WPD-OTV-400 that is continuously being supplied with lunar water from the lunar poles from reusable CLV-5A and CLV-5B water shuttles. Once the WPD-OTV-400 filled with 240 tonnes of water in addition to being fully fueled with 400 tonnes of LOX/LH2 propellant, it will redeploy itself back to LEO where most of the 240 tonnes of water will be converted into LOX/LH2 propellant. Large solar arrays deployed by previous SLS launched at both LEO and EML4 will provide all of the electricity necessary to power the depot electrolysis plants and cryocoolers for converting water into liquid hydrogen and oxygen.

The Odyssey

Once at EML4, the two ETLV-2
vehicles with dock at the twin AGH ports for the Odyssey interplanetary
vehicle, transferring the 12 astronauts to the vessel destined for
Mars. The Odyssey interplanetary vehicle consist of an OTV-400 orbital
transfer
vehicle capable of storing up to 400 tonnes of LOX/LH2 propellant; an
AGH artificial gravity habitat shielded with 30 cm of lunar water; and
two ETLV-2 crew transport vehicles with only 6 tonnes of propellant
within each vehicle. These Odyssey components will be deployed to EML4 by
three separate SLS launches the previous year (2029).

Inside
of the Odyssey, the 12 astronauts will be greeted by six others astronauts who are permanently stationed at an EML4 AGH
(Artificial Gravity Habitat) space station. The permanent artificial gravity space station is protected from
dangerous levels of cosmic radiation and major solar events with a
shielding of lunar iron slabs that were manufactured by 3D printers on
the surface of the Moon and exported to EML4 by reusable CLV-5A cargo
landing vehicles. The EML4 stationed astronauts will return to their AGH
space station after helping to prepare the crew of the Odyssey for their interplanetary launch.

Top: Odyssey trajectory burn configuration. 2nd from top: After the trajectory burn the OTV-400, AGH, and twin ETV-2 shuttles separate in preparation for vehicle reconfiguration. 3rd from top: After AGH shifts 90 degrees and then commences to rotate along an axis between the separated OTV-400 and the ETLV-2 vehicles. 4th from the top: AGH internal cables and external retractable booms expand to produce 0.5g of simulated gravity. Bottom: The two ETLV-2 vehicles rotate to match the rotation of the AGH before they dock with the structure at the pressurized central docking module.

Interplanetary Space

Since the Odyssey mission will take a longer route to Mars that will
allow it to also fly past the planet Venus, the OTV-400 will require
maximum amount of propellant. But launching from EML4 instead of LEO will still shave off nearly 2.8
km/s of its delta-v requirements. The WPD-OTV-400 will fill the Odyssey's OTV-400
with nearly 400 tonnes of LOX/LH2 propellant and its twin AGH habitat modules with more than 200 tonnes of water for radiation shielding (142 tonnes) plus water for drinking,
washing, food preparation, and the production of air.

Initially, the Odyssey will
be in a linear configuration when it departs from cis-lunar space. But
after the Mars Transfer Orbit trajectory burns, the Odyssey components will separate in order to
reconfigure itself so that the AGH can rotate and expand the light weight retractable booms surrounding the cables connecting its twin habitat modules. Extending about 112 meters away from the central axis while rotating at 2 rpm, each of the twin modules will experience a simulated gravity of approximately 0.5g. The astronauts within each habitat module would, therefore, feel a simulated gravity half that of being on the surface of the Earth but still significantly higher than the gravity experienced on the surface of the Moon or Mars. In theory, the artificial gravity environment should substantially reduce and possibly even eliminate the deleterious effects associated with microgravity environments. Artificial gravity should also
create a much more comfortable and familiar physical and psychological environment
during their 22 month mission.

In a trajectory configuration, the Odyssey flies past the plant Venus on its way to Mars.

Venus

In July of 2030, after nearly five months
of interplanetary travel, the Odyssey will reconfigure itself into a
linear configuration just a few days before it nears the planet
Venus. This will allow the OTV-400 to make some minor trajectory burns as they Odyssey flies past Venus on its way to Mars. During the flyby, the astronauts aboard the Odyssey could utilize one of the ETLV-2
vehicles to get a better look at Venus during the flyby, taking photographs and videos of the veiled planet. After the trajectory
burns, the Odyssey
will once again reconfigure itself so that the AGH can once again produce an artificial gravity environment for the astronauts.

After the AGH habitats dump their water shielding, the Odyssey reconfigures to a linear position in order to enter high Mars orbit.

2031

High Mars Orbit

Before the arrival of the Odyssey, two WPD-OTV-400 water/propellant depots will already be in high Mars orbit along
with a pair of large solar electric arrays, originally launched to high Mars orbit during the previous launch window in 2028.

In February of 2031, several hours to a few days before the Odyssey’s rendezvous with
Mars, the rotating AGH modules will dump their 142 tonnes of water shielding. This will cut the total inert mass of the
Odyssey nearly in half which will substantially reducing the amount of propellant required to
place the interplanetary vessel into a high Mars orbit. After the final trajectory burn places the Odyssey into orbit, the AGH will separate from the Odyssey to rendezvous with one of the WPD-OTV-400 water/propellant depots to replace the water shielding for its habitat modules.

Once the AGH modules are fully water shielded again, the Odyssey will reconfigure itself so
that the AGH can produce 0.5 g of simulated gravity and so that the crew can begin to conduct their exploration of the two martian moons.

The WPD-OTV-400, in high Mars orbit, rendezvous with the AGH to replenish the 142 tonnes of water for radiation shielding the habitat modules.

Fully water shielded again, the AGH begins to rotate again at 0.5 Gs, expanding its retractable boom and twin habitat modules.

Deimos

One of the ETLV-2 vehicles will dock
with one of the orbiting water/propellant depots in high Mars orbit,
accessing the amount of propellant needed for its crewed mission to the
surface of Deimos and back to the Odyssey. Six astronauts will participate in the three day exploration of the outer martian moon. After the astronauts land on the
surface of Deimos, a few mobile robots will be deployed that will be
teleoperated by astronauts still remaining at the AGH. For over a month, these robots will explore various regions on the surface of Deimos, taking videos and photographs and collecting samples. These samples will be retrieved a month later by the
second six person crew from the Odyssey to land on the surface of Deimos.

ETLV-2 on its way towards the first crewed landing on Deimos.

Phobos

After the first crewed mission to Deimos, Phobos will be the next destination for a crewed ETLV-2.
Again, six astronauts will participate in three days of exploration. After the astronauts land on Phobos, mobile robots will be deployed to explore various regions on the surface of of the inner moon, taking videos and photographs and collecting samples. These
samples will also be retrieved, a month later, by the
second six person crew from the Odyssey sent to the surface of Phobos

Preparations for Departure

After two
months in orbit around Mars, the
OTV-400 will fill its tanks up with more than 300 tonnes of
LOX/LH2 propellant from one of the WPD-OTV-400 water/propellant depots.

Reconfigured
into a linear configuration, the Odyssey will depart from Mars
in April of 2031. After the trajectory burns that launches the Odyssey into an Earth Transfer Orbit, the Odyssey will, once again, transform into an
artificial gravity producing configuration.

One of the nearly depleted
WPD-OTV-400 water/
propellant depots will also leave Mars for cis-lunar space in order to
resupply itself with lunar water and propellant for a return to Mars orbit in 2033.

With the solar power plant for the WPD-OTV-400 in the background, the OTV-400 rendezvous with the propellant depot to add LOX/LH2 for the Odyssey's return journey to cis-lunar space.

The Return to Cis-Lunar Space

In
December of 2031, the AGH will once again dump its water shielding as it nears its rendezvous with cis-lunar space. Once it is
linearly reconfigured, the final trajectory burns will place the Odyssey
and its crew back in halo orbit at EML4.

The crew will then be
transferred by two ETLV-2 shuttles to the EML4 AGH space station for a
few days before being transferred again by two ETLV-2 shuttles to LEO. Commercial Crew vehicles will then transport the astronauts to the Earth's surface, pioneers and heroes to be welcomed back by the cheering crowds on Earth.

The Odyssey interplanetary spacecraft returns to EML4. Two ETLV-2 shuttles docked at a permanent AGH space station at the Earth-Moon Lagrange point will transport the crew back to the EML4 space station for a few days before the 12 person crew is eventually transported to LEO and then back to the surface of the Earth aboard Commercial Crew vehicles.

The Next Interplanetary Mission

NASA, on the other
hand, will be preparing for the next crewed mission to Mars orbit which will be launched from EML4 in
2033. The 2033 mission will deploy the first permanent iron shielded AGH space station into high Mars orbit. The 2033 mission will also deploy the first unmanned
ADEPT protected ETLV-2 vehicles to the surface of Mars to test ETLV-2 s
ability to land large masses on the surface of Mars while testing the ability of the ETLV-2 to return to orbit from the surface of Mars.
Tele-operated robots will also be deployed by the ETLV-2 vehicles to retrieve regolith samples to
be transported to Mars orbit and eventually back to Earth.

Monday, September 7, 2015

For NASA and its future SLS program, developing a reusable single staged extraterrestrial landing vehicle (ETLV) could allow America to send astronauts to the surface of the Moon, Mars, and even to the surfaces of the moons of Mars. Such an ETLV could be used to conveniently transport astronauts from EML1 (Earth-Moon Lagrange point 1) to the surface of the Moon and back to EML1 on a single fueling of LOX/LH2 propellant. NASA astronauts could reach EML1 and return to the Earth via an SLS launched Orion spacecraft.

Eventually, by deploying ETLV derived orbital propellant depots at points of departure and
destination, such a reusable spacecraft could also be used as an
orbital transfer vehicle, transporting astronauts between LEO and the
Earth-Moon Lagrange points. This would allow Commercial Crew vehicles to shuttle NASA astronauts to LEO to dock with an ETLV destined for EML1 or to return astronauts from an ETLV returning from EML1.

By utilizing ADEPT
deceleration shields, such an ETLV could also be used to transport
humans from low Mars orbit to the surface of Mars and back into Mars orbit on a single fueling. With an ADEPT decelerator, the delta-v
requirement to land on the lunar surface from orbit is only 0.51 km/s.
The delta-v to travel from the surface of Mars back to Mars orbit is 4.4
km/s. Propellant depot located in Low Mars Orbit would allow the
vehicle to refuel in order to travel to orbital habitats or
interplanetary vehicles located in High Mars Orbits. Traveling between
High Mars Orbit and the Earth-Moon Lagrange points has the lowest
delta-v requirements between Mars orbit and cis-lunar space.

A reusable ETLV located at propellant producing lunar outpost that utilizes a reusable CTLV (Cryotanker Landing Vehicle) could also allow humans to continuously explore practically every region on the lunar surface without the need of any additional SLS launches from Earth-- dramatically reducing the cost of the human exploration of the Moon

Once a permanent outpost is established on the surface of the Moon, the entire lunar surface, including its craters, could be continuously explored by robotic lunar rovers tele-operated from Earth. Such solar and nuclear powered mobile robots could also retrieve regolith samples for return to the outpost for study and, eventually, transported back to Earth. Such mobile robots could also be used to locate interesting sites for future human exploration.

Because annual levels of cosmic radiation on the lunar surface can range from 11 Rem during solar maximum conditions to as high as 38 Rem during solar minimum conditions, astronauts living on the Moon for several months or several years will have to minimize their radiation exposure by mostly living inside regolith shielded habitats to reduce annual radiation exposure to less than 5 Rem (the maximum level of radiation exposure for radiation workers on Earth) during solar maximum and minimum conditions. This can easily be done by landing habitats on the lunar surface that can automatically deploy regolith walls that can be easily filled with approximately 2 meters of lunar regolith.

If astronauts spend about 10% of their time outside of their shielded habitats (2.4 hours per day or 16.8 hours per week), their additional exposure after a year would only range from 1.1 Rem to 3.8 Rem. A 25 year old female could live and work on the Moon for a decade and still not exceed her maximum lifetime limit of 100 Rem. Astronauts minimizing their radiation exposure by exploring the lunar surface for just four to eight hours per week could, therefore, explore various regions on the Moon on a weekly basis-- if they could have easy access to such regions.

Since ground vehicles transporting crews across the lunar surface are not likely to exceed 20 km per hour in average speed, the maximum area that could be explored by pressure suited astronauts is not likely to exceed a distance of more than 80 kilometers away from a shielded lunar outpost.

However, rocket powered sub-orbital Lunar Hoppers hurtling along parabolic arcs have long been advocated as a way for humans to explore more distant regions on the Moon-- far beyond a permanent lunar outpost. But such missions would require the reusable vehicle to have-- enough propellant-- to:

1. take off from the outpost on a suborbital trajectory,

2. land at the site intended to be explored,

3. take off again on a suborbital trajectory,

and,

4. land back at the lunar outpost.

The delta-v and travel times for possible crewed suborbital hops on the lunar surface.

David Hop, on his popular space blog, has done some interesting calculations, suggesting that lunar hoppers could transport humans anywhere on the lunar surface in less than an hour with a maximum delta-v of only 1.68 km/s. So transportation between lunar outpost and lunar cities could be conveniently fast and easy-- as long as every lunar outpost or lunar city can refuel the Hopper for its next suborbital destination.

An ETLV fueled with a maximum of 24 tonnes of LOX/LH2 propellant (originally designed for round trips between EML1 and the lunar surface) could transport astronauts within a 1300 kilometer radius from a lunar outpost and back. Beyond 1300 kilometers (45 degrees), however, such an ETLV would not have enough propellant for its return trip to the lunar outpost.

Since the distance from the poles to the lunar equator would be 2700 kilometers away and to the opposite pole, more than 5400 kilometers away, a single polar outpost would pretty much confine human exploration via Hoppers mostly to it's polar region.

One way to overcome such geographical limitations would be to launch crewed ETLVs to EML1. There it would add additional rocket fuel from a propellant depot (WPD-OTV-5A) located at EML1 for a round trip mission from the Lagrange point to the lunar site chosen to be explored. After the completion of the exploratory mission, the ETLV would return to EML1 to add propellant for its return trip to its original lunar outpost.

Lunar Exploration via lunar outpost and EML1 propellant depot

1. Crewed ETLV-2 launched from lunar outpost to EML1 (less than 12 hours at high delta-v or two days at a lower delta-v))

2. ETLV-2 rendezvous with WPD-OTV-5A adding enough propellant for a round trip from the lunar surface and back to EML1

3. ETLV-2 travels to lunar orbit and lands at lunar site (~2 days of travel) for a few hours or a few days of exploration

4.
ETLV-2 launches itself back to EML1 (~2 days of travel) and rendezvous
with WPD-OTV-5A to refuel for trip back to lunar outpost

5. ETLV-2 departs from EML1 to return to lunar outpost (less than 12 hours or up to two days)

This scenario requires only one vehicle (ETLV-2). In theory, it would allow sorties to
be conducted practically anyplace on the lunar surface on a weekly basis. This method, however, would require at least five to eight days of travel time-- excluding the time spent exploring the region on the lunar surface. So each lunar sortie would expose astronauts to five to eight continuous days cosmic radiation outside of a regolith shielded outpost-- for perhaps just a few hours or a few of days of exploration at a particular lunar site.

Alternatively, pre-deploying a mobile propellant depot (MCT) at the site intended to be explored could minimize astronauts radiation exposure during a lunar sortie.

ETLV-2 lands near a pre-deployed mobile cryotanker (MCT) after it's suborbital flight to a predetermined lunar exploratory site. The MCT will provide the ETLV-2 with additional LOX/LH2 for its return flight to a polar outpost.

Lunar exploration utilizing mobile cryotankers

1. A solar and fuel cell powered mobile cryotanker (MCT) with up to
12 tonnes of propellant is sent to a lunar exploratory site (distance traveled: 300 km/day)
in less than a month

2. Crewed ETLV-2 launched from
lunar outpost to lunar exploratory site (less than an hour) with a few
tonnes of extra fuel for the return trip to the outpost.

3. MCT adds enough additional fuel to the ETLV-2 for it to return to the lunar outpost

4. With added fuel, the ETLV-2 launches itself back to lunar outpost in less than an hour of travel time

5. The mobile MCT returns to the lunar outpost after a few weeks of travel time.

This scenario dramatically reduces astronaut's travel time to less than two hours of continuous radiation exposure. Preparing for such lunar sorties, however, would require a mobile cryotanker to be deployed to the exploratory site a few weeks before the crewed mission. And then a few weeks would have to be allowed for the cryotanker's return to the lunar outpost.

However, there is another way that lunar sorties from a lunar outpost could be conducted on a daily basis while also minimizing cosmic radiation exposure. This scenario would require an ETLV to be launched in an orbital plane above the intended site to be explored along with a reusable CTLV (Cryotanker Landing Vehicle).

Crewed ETLV-2 rendezvous with an unmanned CTLV-5B cryotanker in the same orbital plane as the intended lunar exploratory site and the lunar outpost. After the lunar exploratory mission is completed, both the ETLV-2 and the CTLV-5B will return to the lunar outpost to be used again for future lunar exploratory missions.

Lunar exploration utilizing an ETLV-2 and CTLV-5B in lunar orbit

1. CTLV-5B launched from lunar outpost into an orbital plane directly above the intended landing site

2. Crewed ETLV-2 launched from lunar outpost into the same orbital plane

3. ETLV-2 rendezvous with CTLV-5B adding enough propellant for a round trip from the lunar surface and back into orbit

4. ETLV-2 lands at lunar exploratory site for a few hours or a few days of exploration

5. ETLV-2 launches itself back into orbit along the same orbital plane

7.
CTLV-5B uses the its remaining amount of propellant to land back at the
lunar outpost to be eventually refueled to assist in the next sortie
mission on the lunar surface

ETLV-2 at an exploratory site on the lunar surface. Distances exceeding 1300 kilometers away from a propellant producing lunar outpost will require the ETLV-2 to use its remaining fuel to launch itself back into the same orbital plane as an orbiting CTLV-5B cryotanker, in order to add the needed fuel necessary for it to return to the lunar outpost.

The CTLV is simply the CLV (Cargo Landing Vehicle) without the cargo. So
no new extraterrestrial vehicle would have to be developed in order to
utilize the CLV as a reusable propellant vehicle (CTLV).

While this
scenario requires two reusable launch vehicles (ETLV-2 and the CTLV-5B),
it has the advantage of being able to deploy astronauts quickly to an
exploration site in just a few hours. Most of the few hours of travel time for astronauts would be spent in lunar orbit while rendezvousing with the CTLV-5B propellant depot to add more propellant.

In the early 2030s, I imagine that most of the water produced at a lunar outpost would probably be exported to one of the Earth-Moon Lagrange points to provide water for future interplanetary missions to Mars, Venus, ESL4, ESL5, and the NEO asteroids: water for drinking, washing, the production of air, radiation shielding, and LH2/LOX propellant.

But some of the water derived from the lunar poles could also be used for the production of lunar propellant intended for the domestic human exploration of the lunar surface. This could allow reusable Extraterrestrial Landing Vehicles to cheaply and conveniently transport astronauts to practically every region on the lunar surface for a few hours or even a few days of exploration. So the production and export of lunar water could not only greatly enhance NASA's ability to send humans to Mars but it could also usher in a new renaissance of human exploration-- on the lunar surface.

Tuesday, April 28, 2015

Terrestrial and off-shore nuclear power plants could safely and economically provide all of the base load electricity requirements for future carbon neutral industrial economies. The additional-- peak load-- electrical demands for an industrial region could also be supplied by carbon neutral methanol electric power plants-- if nuclear electricity was also utilized to produce renewable methanol derived from biowaste and waste water resourcesMethanol (CH3OH) is, of course, the simplest alcohol, producing only carbon dioxide (CO2) and water after combustion with oxygen. The production of methyl alcohol through the pyrolysis of carbon based materials and their distillation has been known since the time of the ancient Egyptians. Modern techniques of methanol production utilize pyrolysis to produce syngas (synthetic natural gas), a gaseous mixture of consisting of carbon monoxide, carbon dioxide, and hydrogen that is then converted into methanol.

Since approximately 65% to 75% of the CO2 content is wasted during the synthesis of syngas into to methanol, introducing additional hydrogen into the synthesis process could
potentially increase the production of methanol by three to four times. Sources of carbon neutral hydrogen could, therefore, be produced through nuclear, hydroelectric, wind, and solar electric power through the
electrolysis of water.

Plasma arc pyrolysis plants, a commercial technology that's already in existence, could be used for the conversion of urban and rural biowaste (garbage and sewage) into syngas. Additional hydrogen can be added to the mix through the production of hydrogen through the electrolysis of water at an electrolysis plant. The syngas and additional hydrogen can then converted into methanol at a alcohol methanol synthesis plant.

Diagram of a methanol biowaste complex for the production of methanol and electricity.

Carbon neutral sources of electricity could come from nuclear, hydroelectic, wind, and solar power plants. Because the sun doesn't always shine and the wind doesn't always blow, wind and solar facilities only offer intermittent supplies of carbon neutral electricity to the electric grid. While hydroelectric power plants can supply carbon neutral electricity to the grid 24/7, this renewable energy source has already reached its maximum capacity in the US and can actually supply less power to the grid during periods of drought-- as is currently the occurring in drought stricken California.

Nuclear power plants, on the other hand, can supply carbon neutral electricity to the grid 24 hours per day. Except during periods of refueling (once every three years), current light water nuclear power plants in the US have an electrical capacity exceeding 90%. Nuclear power currently produces about
20% of America's electricity supply. But there is currently enough room--
at existing US nuclear sites-- to increase nuclear power production in the US by at least four to five times
the current nuclear capacity without the need to add new locations within the continental US. This could easily be done by gradually adding the next generation of Small Modular Reactors (SMR) to existing sites over the next twenty to thirty years.

A methanol complex using carbon neutral electricity from nuclear and
renewable energy could produce methanol from the pyrolysis of urban and
rural garbage and sewage-- solving the problems of urban and rural refuse while also producing clean energy. The production of hydrogen from the
electrolysis of water could substantial increase methyl alcohol production. Domestic sources of carbon neutral methanol could then be used to fuel methanol
electric power plants during peak load demands. The production
of electricity from a methanol electric power plant could be further increased if the waste oxygen from the production of hydrogen were utilized during fuel combustion instead of air which contains only 20% oxygen and 80% nitrogen.

While
the CO2 produced from a methanol electric power plant
could be exhausted into the air without increasing the net amount of CO2
in the Earth's atmosphere, the waste carbon dioxide from the flu gas could also be recycled. Post combustion and pre- combustion CO2 capture facilities can
collect 85 to 90% of CO2 from flu gas. And power plants that used oxygen can capture as
much as 90 to 97% of the CO2 produced from flu gas. Pumping the waste CO2
into the methanol synthesis plants could nearly double the production of
renewable methanol if even more hydrogen is added to the mix.

Any excess production of methanol from a methanol electric complex would be a valuable commodity that could be exported. Exported methanol could be used for the base load production of electricity in areas with no access to nuclear power or it could be converted into gasoline or dimethyl ether for trucks and automobiles. Methanol would also be of value to industrial chemical companies.

TVA’s, Sequoyah Nuclear Plant (Credit TVA).

Despite the accidents at Fukushima and Chernobyl, terrestrially based commercial nuclear
power are still the safest source of electricity production ever
invented. But floating commercial nuclear reactors deployed several kilometers off marine coastlines or even deployed far out into the ocean could enhance nuclear safety even further.

The Earth's oceans, of course, are certainly no strangers to nuclear power.
There are over 140 nuclear powered ships and submarines roaming the
Earth's oceans and seas with more than 12,000 reactor years of marine
operations
accumulated since 1954.

More than 100 million Americans currently live within 80 kilometers of a commercial nuclear reactor. But undersea electric cables more than 1000 kilometers away from coastlines are possible. Floating nuclear power facilities could be deployed more than 300 kilometers from an American coastline while still being within the US's 200 nautical mile (370 kilometer) exclusive coastal economic zone. Such floating
reactors could, therefore, be deployed far beyond the 80 kilometer
exclusion zone recommended by the United States during the height of the Fukushima
nuclear accident.

Of course, a Fukushima type of incident would be impossible for a floating nuclear facilities located in the open ocean since water is a natural coolant for light water reactor fuel. Ocean waters would serve as an infinite heat sink for fissile material-- essentially making nuclear meltdowns impossible for floating reactors placed below the water level.
Floating nuclear reactors placed dozens of kilometers offshore would also be
immune to potential damage from earthquakes and tsunamis.

The safety of floating nuclear facilities from potential harm from terrorist or other hostile political groups could be enhanced by naval security from US Coast Guard or other US government authorized security forces. Potential
damage to the reactor from a torpedo could also easily be
prevented with an extensive network of torpedo nets surround the nuclear power facilities.

But, again, even if an attack on a floating nuclear facility was successful, the ocean water would immediately prevent any melting of the nuclear material to occur. Water also acts as a natural radiation shield. Just a few meters of water can reduce ionizing radiation to harmless levels of exposure near
the radioactive material.

Japanese Methanol Tanker (Credit: SHIN KURUSHIMA DOCKYARD CO)

Ocean Nuclear power plants could also
be remotely deployed, more than a thousands of kilometers away from
coastlines for the production of electricity. Methanol powered ships
could transport garbage from coastal towns and cities to floating
biowaste pyrolysis, water electrolysis, and methanol synthesis plants
remotely powered by underwater electric cables from Ocean Nuclear Power
plants just a few kilometers away. The methanol could then be shipped to
coastal towns and cities all over the world for the production of
electricity or for conversion into gasoline or dimethyl ether for diesel
fuel engines.

First Methanol Fueled Ferry (Credit Stena Line)

Combined with nuclear and renewable energy, renewable methanol fueled
peak load power plants could finally end the need for greenhouse gas
polluting coal and natural gas power plants in the US and in the rest of
the world.

Thursday, March 19, 2015

ETLV-2 coupled with an ADEPT deceleration shield on its way the martian surface

by Marcel F. Williams

"As we reported in August 2013, even after the SLS and Orion
are fully developed and ready to transport crew NASA will continue to
face significant challenges concerning the long-term sustainability of
its human exploration program. For example, unless NASA begins a
program to develop landers and surface systems its astronauts will be
limited to orbital missions of Mars. Given the time and money necessary
to develop these systems, it is unlikely that NASA would be able to
conduct any manned surface exploration missions until the late 2030s at
the earliest."NASA Office of Inspector GeneralFebruary 25, 2015

-------------------------

It is generally agreed by both the Congress and the Executive Branch that sending humans to the surface of Mars, sometime in the 2030s, should be the long term goal of the National Aeronautics and Space Administration (NASA). However, the intermediate destination during the 2020s needed to develop and to mature such space faring capability has been subject to controversy. While some have advocated a return to the lunar surface as a bridge towards Mars, others have argued that the development of a lunar architecture could actually siphon off necessary funds for sending humans to the martian surface.

The extraterrestrial deployment of huge amounts of water will be essential for any interplanetary journey. Even if some future Mars vessels are
xenon fueled solar electric interplanetary vehicles, crewed missions between cis-lunar space and Mars orbit will still require a substantial tonnage water for
drinking, washing, food preparation, the production of air and for mass shielding habitat modules from the dangers of cosmic radiation and major solar events. The most expensive source of water for an interplanetary vehicle within cis-lunar space is from the Earth's deep gravity well. However, water derived from ice in the Moon's polar regions would be a substantially cheaper source since the Moon has a significantly lower gravity well. Water, of course, could also be used for the production of LOX/LH2 propellant
necessary for voyages between cis-lunar space and Mars orbit.

ADEPT payload deployment scenarios for Mars (Credit: NASA)

Because of its thin atmosphere and higher gravity, Mars is a very different world than the Moon. Still,
habitat modules, propellant producing water depots, and mobile ground vehicles that could be
utilized on the surface of the Moon could also be used on the surface of Mars. This could save NASA enormous amounts of money since basically the same surface architecture for the Moon could also be deployed on the surface of Mars. So no new surface infrastructure unique to Mars would not have to be developed.

Vehicles designed to deploy cargoes and crews to the lunar surface could also be used to deploy cargoes and crews to the surface of Mars. But in order to safely deploy cargoes and crews to the martian surface, such vehicles will need to be shielded and decelerated through the thin martian atmosphere through the ADEPT or HIAD technologies currently being developed by NASA.

HIAD and ADEPT
technologies simply use a large expandable heat shield to protect a
spacecraft from the frictional heating of the thin martian atmosphere (100 thinner than the Earth's atmosphere)
while also decelerating the vehicle enough to eventually allow the
vehicle to utilize retrorockets to hover and land on the martian
surface. The weight of these decelerating heat shields approach 50% of
the payload being deployed to the surface. But NASA believes that these
technologies should enable them to deploy as much as 40 tonnes of payload
to the martian surface.

C-ETLV-5 cargo lander and ETLV-2 crew lander for deploying cargoes and crew to the surface of the Moon, Mars, and on the surfaces of the moons of Mars

In July of 1962, NASA invited private companies to submit proposals for the development of a Lunar Module (LM). Seven years later, this lunar landing craft took Neil Armstrong and Buzz Aldrin to the surface of the Moon. Assuming a similar length of time for the development of a new Extraterrestrial Landing Vehicle (ETLV), proposals submitted for an ETLV in 2016 could result in the return of humans to the lunar surface by 2023. Thus, by the 2030's, the ETLV will be a mature landing vehicle ready to deploy humans and cargo to the surface of Mars.

If we assume that NASA's annual human spaceflight related budget remains at approximately $8 billion a year over the next 25 years, then NASA will spend approximately $200 billion over the next quarter of a century on human spaceflight related technology, operations, and activities. $8 billion a year should be enough for NASA to establish a permanent human presence on the surface of the Moon in the 2020s and on the surface of Mars in the 2030s-- if such efforts are prioritized-- especially if NASA is no longer burdened with the $3 billion a year ISS program during the next two decades.

A reusable single staged LOX/LH2 ETLV capable of a round trips between the Earth-Moon Lagrange points and the lunar surface should also be capable of easily transporting crews from the surface of Mars to Low Mars Orbit-- or even all the way to the surface of Mars's inner moon, Phobos. HIAD or ADEPT deceleration shield would, again, be used to deploy the crewed ETLV safely to the martian surface. The cost of developing a crewed lunar landing vehicle has been estimated to be as much as $8 to $12 billion. So over the course of seven years, the cost for developing an ETLV could range from $1.1 billion to $1.7 billion per year. And that's a cost that is certainly affordable with an $8 billion a year human spaceflight related budget.

ETLV-2 at a sintered landing area being refueled with LOX and LH2 for its departure to Mars orbit.

Regolith shielded lunar habitats cheaply derived from SLS propellant tank technology could also be deployed to the martian surface using a lunar cargo lander and a, of course, a HIAD or ADEPT deceleration shield. Regolith shielding a martian habitat to a similar degree as a lunar habitat will be necessary since the level of cosmic ray exposure on the martian surface is not substantially lower than on the lunar surface.

Three habitat modules previously deployed by a C-ETLV-5. The pressurized habitats are shielded with 2 meters of martian regolith contained within the automatically deployed regolith wall. Solar charged batteries are used to provide power for the habitat at night. But nearby nuclear power units buried beneath the regolith will also provide supplementary power for the outpost.

Ionizing Radiation on the Surface of the Moon:

38 Rem - annual amount of cosmic radiation on the Lunar surface during the solar minimum11 Rem - annual amount of cosmic radiation on the Lunar surface during the solar maximumIonizing Radiation on the Surface of Mars:33 Rem - annual rate of cosmic radiation on the surface of Mars beneath 16 gm/cm3 of Martian atmosphere during the solar minimum8 Rem - annual rate of cosmic radiation on the surface of Mars beneath 16 gm/cm3 of Martian atmosphere during the solar maximum

Percentage of water contained in different regions on the martian surface.

Lunar water collecting mobile vehicles using microwaves used to extract water from the regolith at the lunar poles could also be used on much of the martian surface. The water content of the lunar regolith at the lunar poles has been estimated to be approximately 5%. The water content of the martian regolith at the lower latitudes ranges from approximately 1 to 7% depending on the region. But there are large regions near the martian equator that may have regolith with a water content as high as 7%. At higher latitudes, the water content may be as high as 30%. And at the martian poles, the water content could be as much as 70%.

Mobile water tanker and microwave water extraction robot on Mars.

Solar powered WPD-LV-5 water storage and propellant producing unit on the surface of Mars. Additional power can be provided by nearby nuclear power units buried beneath the martian regolith.

Small nuclear power units will probably be necessary to supplement the solar electric power supply at a martian outpost. While batteries and electric flywheels charged during the daytime could provide power for an outpost a night, dust storms could substantially reduce solar electricity for up to a month with dust particles blanketing the solar panels. But small nuclear power units could run 24 hours a day for several years before having to be replaced. So during dust storms, it might be wise for the outpost to contract the solar panels while mostly relying on nuclear power until the storm is over. Such nuclear power units for Mars
should also probably be initially tested on the lunar surface in the
2020s for a few years before they are eventually deployed at a martian outpost in the 2030s.

Nuclear power unit on the Moon with its reactor buried beneath the regolith and its cooling panels above the surface. Such units could also be utilized on the martian surface (Credit: NASA).

"The knowledge that we have now is but a fraction of the knowledge we must get, whether for peaceful use or for national defense. We must depend on intensive research to acquire the further knowledge we need ... These are truths that every scientist knows. They are truths that the American people need to understand." (Harry S. Truman 1948).